This invention relates to guide rollers supported for rotation about a longitudinal axis and having a cylindrical, concave or convex peripheral surface.
Such guide rollers are used, for example, as pulleys in synchronous belt drives or belt tensioning devices by which a drive belt extending between an internal combustion engine and one or more auxiliary components is adjusted to provide the belt tension necessary for reliable operation. Such a belt tensioning device is disclosed, for example, in German Offenlegungsschrift No. 38 24 645 in which a guide roller supported on a spring-loaded lever arm has substantially cylindrical shape including a cylindrical surface and has raised rims at the sides of the cylindrical surface to assure better guidance of a drive belt on the roller.
In the operation of devices provided with drive belts, background noise is generated in the unsupported sections of a drive belt extending between drive wheels, pulleys and guide rollers as a result of sympathetic vibrations. These vibrations are transferred through the drive wheels to the engine structure and are transmitted through the air as sound. As used herein the term "guide roller" includes a pulley, drive wheel, tension roller or other rotatable member having a peripheral surface arranged to be engaged by a drive belt.